This invention relates generally to heat exchangers, and more particularly to a tube bundle heat exchanger with baffles.
In conventional tube bundle heat exchangers, baffles are used to cause the heating medium to flow both crossways and parallel to the tube bundle in order to utilize the heat exchanger surface as completely as possible. The heat transfer takes place by convection. The baffles generally slide over the tubes and are fastened at prescribed points to a casing in which the tubes are housed. Between adjacent prescribed fastening points exists a slot between the baffle and the casing. The slots constitute leaks which reduce the efficiency of the heat exchanger. The severity of the leaks vary with baffle design and with different methods of attaching the baffles to the casing.
In heat exchanges in which fluids flow at high velocities, the velocity of the fluid flowing through the slots can become so high that corrosion and erosion occur primarily due to cavitation at the baffle and at the adjacent tube and casing.
It is therefore an object of this invention to provide a heat exchanger of high efficiency and without leak flows.
According to a preferred embodiment of the present invention, the tube bundles of the heat exchanger are housed in an inner casing. The heating medium flows both inside and outside of the inner casing so that the inner casing is not subject to stresses caused by pressure. Baffles included in the heat exchanger are connected to the inner casing in such a way as to prevent leak flows. Adjacent tubes of the tube bundle are separated by a zigzag-dividing wall. The dividing wall and the baffles form rerouting channels for the heating medium. Efficient heat transfer is obtained by locating the tubes of the tube bundle longitudinally in essentially longitudinal rerouting channels.